Multiple applications which require eliminating reflections of electromagnetic radiation are known.
Thus, for example, microwave absorbers are made by modifying dielectric properties, in other words, the dielectric permittivity or the magnetic permeability of determined materials. To that end, it is necessary to disperse small sized metallic elements in a dielectric matrix. Various inventions show these types of solutions, as is the case of U.S. Pat. No. 5,147,718, in which a radar absorber based on the dispersion of carbonyl iron powder into a paint is described. The solution is also shown in patent document WO 03/004202 which shows a method for making an electromagnetic radiation absorber based on the dispersion of flakes of an iron-silicon alloy. The solution is also shown in U.S. Pat. No. 5,085,931 in which an electromagnetic radiation absorber is formed by dispersing acicular magnetic filaments into a dielectric matrix.
Some absorbers based on amorphous magnetic microwires obtained by the Taylor technique (“The preparation, properties and applications of some glass coated metal filaments prepared by the Taylor-wire process”, W. Donald et al., Journal of Material Science, 31, 1996, pp. 1139-1148) can be included among magnetic type absorbers. This type of absorber can be a dielectric matrix in which amorphous magnetic microwires with high magnetic anisotropy having magnetic resonance properties are randomly distributed, as described in European patent EP-1675217.